Selective Naked-Eye Detection of Hg²⁺ through an Efficient Turn-On Photoinduced Electron Transfer Fluorescent Probe and Its Real Applications

Abstract

A simple molecular fluorescent probe 5 has been designed and synthesized by appending anthracene and benzhydryl moieties through a piperazine bridge. The probe upon interaction with different metal ions showed high selectivity and sensitivity (2 ppb) for Hg(2+) through fluorescence "turn-on" response in HEPES buffer. The significant fluorescence enhancement (~10-fold) is attributable to PET arrest due to complexation with nitrogen atoms of the piperazine unit and Hg(2+) in 1:2 stoichiometry, in which a naked-eye sensitive fluorescent blue color of solution changed to a blue-green (switched-on). As a proof of concept, promising prospects for application in environmental and biological sciences 5 have been utilized to detect Hg(2+) sensitively in real samples, on cellulose paper strips, in protein medium (like BSA), and intracellularly in HeLa cells. Moreover, the optical behavior of 5 upon providing different chemical inputs has been utilized to construct individual logic gates and a reusable combinational logic circuit. The combinational circuit (switch ON mode; OR logic gate) is easily resettable to the original position (switch OFF mode; INHIBIT logic gate) by applying reset chemical inputs (OH(-) and PO4(3-)) with great reproducibility.

A coumarin-derived useful scaffold exhibiting Cu2+ induced fluorescence quenching and fluoride sensing (On–Off–On) via copper displacement approach

“…Considering the possible interference that other components may cause in real samples the level of Cu 2+ in real water samples was determined using the standard addition method [31][32]. Prior to real sample detection probe 6…”

A highly selective colorimetric and long‐wavelength fluorescent probe for the detection of Hg2+

“…Furthermore, very small amounts of mercury causes serious harm to humans. Once mercury is absorbed through the skin or respiratory tract, it will pose a threat to the body's central nervous system, digestive system and kidney, etc . Therefore, it is significant to develop a highly selective and excellently sensitive method for the detection of mercury ions (Hg 2+ ).…”

Selective and sensitive colorimetric detection of Hg(II) in aqueous solution by quinone-diimidazole ensemble with mimicking YES-OR-INHIBIT logic gate operation

“…A simple molecule with its interesting spectroscopic results mimics the logic operations (YES-OR-INHIBIT). In particular, a system has some chemically encoded information as input and UV-vis or fluorescence as output [40,41]. In the present study, different modes were spotted when the receptor R1 was treated with various cations such as Hg(II), Zn(II) and Cd(II).…”